package com.duubee.btframe.utils;

import java.util.*;

/**
 * 随机数、随机字符串生成工具
 */
public class BtRandomUtil extends Random {

    /**
     * 所有大小写字母和数字
     */
    public static final String allChar = "0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ";
    /**
     * 所有大小写字母
     */
    public static final String letterChar = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ";
    /**
     * 所有数字
     */
    public static final String numberChar = "0123456789";

    /**
     * 返回一个定长的随机纯数字字符串(只包含数字)
     *
     * @param length 随机字符串长度
     * @return 随机字符串
     */
    public static String generateDigitalString(int length) {
        StringBuffer sb = new StringBuffer();
        Random random = new Random();
        for (int i = 0; i < length; i++) {
            sb.append(numberChar.charAt(random.nextInt(numberChar.length())));
        }
        return sb.toString();
    }

    /**
     * 返回一个定长的随机字符串(只包含大小写字母、数字)
     *
     * @param length 随机字符串长度
     * @return 随机字符串
     */
    public static String generateString(int length) {
        StringBuffer sb = new StringBuffer();
        Random random = new Random();
        for (int i = 0; i < length; i++) {
            sb.append(allChar.charAt(random.nextInt(allChar.length())));
        }
        return sb.toString();
    }

    /**
     * 返回一个定长的随机纯字母字符串(只包含大小写字母)
     *
     * @param length 随机字符串长度
     * @return 随机字符串
     */
    public static String generateMixString(int length) {
        StringBuffer sb = new StringBuffer();
        Random random = new Random();
        for (int i = 0; i < length; i++) {
            sb.append(letterChar.charAt(random.nextInt(letterChar.length())));
        }
        return sb.toString();
    }

    /**
     * 返回一个定长的随机纯大写字母字符串(只包含大小写字母)
     *
     * @param length 随机字符串长度
     * @return 随机字符串
     */
    public static String generateLowerString(int length) {
        return generateMixString(length).toLowerCase();
    }

    /**
     * 返回一个定长的随机纯小写字母字符串(只包含大小写字母)
     *
     * @param length 随机字符串长度
     * @return 随机字符串
     */
    public static String generateUpperString(int length) {
        return generateMixString(length).toUpperCase();
    }

    /**
     * 生成一个定长的纯0字符串
     *
     * @param length 字符串长度
     * @return 纯0字符串
     */
    public static String generateZeroString(int length) {
        StringBuffer sb = new StringBuffer();
        for (int i = 0; i < length; i++) {
            sb.append('0');
        }
        return sb.toString();
    }

    /**
     * 根据数字生成一个定长的字符串，长度不够前面补0
     *
     * @param num       数字
     * @param fixdlenth 字符串长度
     * @return 定长的字符串
     */
    public static String toFixdLengthString(long num, int fixdlenth) {
        StringBuffer sb = new StringBuffer();
        String strNum = String.valueOf(num);
        if (fixdlenth - strNum.length() >= 0) {
            sb.append(generateZeroString(fixdlenth - strNum.length()));
        } else {
            throw new RuntimeException("将数字" + num + "转化为长度为" + fixdlenth
                    + "的字符串发生异常！");
        }
        sb.append(strNum);
        return sb.toString();
    }

    /**
     * 根据数字生成一个定长的字符串，长度不够前面补0
     *
     * @param num       数字
     * @param fixdlenth 字符串长度
     * @return 定长的字符串
     */
    public static String toFixdLengthString(int num, int fixdlenth) {
        StringBuffer sb = new StringBuffer();
        String strNum = String.valueOf(num);
        if (fixdlenth - strNum.length() >= 0) {
            sb.append(generateZeroString(fixdlenth - strNum.length()));
        } else {
            throw new RuntimeException("将数字" + num + "转化为长度为" + fixdlenth
                    + "的字符串发生异常！");
        }
        sb.append(strNum);
        return sb.toString();
    }


    private static final long serialVersionUID = 1L;


    public int[] nextInt(int n, int size) {
        if (size > n) {
            size = n;
        }

        Set set = new LinkedHashSet();

        for (int i = 0; i < size; i++) {
            while (true) {
                Integer value = new Integer(nextInt(n));

                if (!set.contains(value)) {
                    set.add(value);

                    break;
                }
            }
        }

        int[] array = new int[set.size()];

        Iterator itr = set.iterator();

        for (int i = 0; i < array.length; i++) {
            array[i] = ((Integer) itr.next()).intValue();
        }

        return array;
    }

    public void randomize(char array[]) {
        int length = array.length;

        for (int i = 0; i < length - 1; i++) {
            int x = nextInt(length);
            char y = array[i];

            array[i] = array[i + x];
            array[i + x] = y;

            length--;
        }
    }

    public void randomize(int array[]) {
        int length = array.length;

        for (int i = 0; i < length - 1; i++) {
            int x = nextInt(length);
            int y = array[i];

            array[i] = array[i + x];
            array[i + x] = y;

            length--;
        }
    }

    public void randomize(List list) {
        int size = list.size();

        for (int i = 0; i <= size; i++) {
            int j = nextInt(size);
            Object obj = list.get(i);

            list.set(i, list.get(i + j));
            list.set(i + j, obj);

            size--;
        }
    }

    public void randomize(Object array[]) {
        int length = array.length;

        for (int i = 0; i < length - 1; i++) {
            int x = nextInt(length);
            Object y = array[i];

            array[i] = array[i + x];
            array[i + x] = y;

            length--;
        }
    }

    public String randomize(String s) {
        if (s == null) {
            return null;
        }

        char[] array = s.toCharArray();

        randomize(array);

        return new String(array);
    }

    public static String[] chars = new String[]{"a", "b", "c", "d", "e", "f",
            "g", "h", "i", "j", "k", "l", "m", "n", "o", "p", "q", "r", "s",
            "t", "u", "v", "w", "x", "y", "z", "0", "1", "2", "3", "4", "5",
            "6", "7", "8", "9", "A", "B", "C", "D", "E", "F", "G", "H", "I",
            "J", "K", "L", "M", "N", "O", "P", "Q", "R", "S", "T", "U", "V",
            "W", "X", "Y", "Z"};


    public static String generateShortUuid() {
        StringBuffer shortBuffer = new StringBuffer();
        String uuid = UUID.randomUUID().toString().replace("-", "");
        for (int i = 0; i < 8; i++) {
            String str = uuid.substring(i * 4, i * 4 + 4);
            int x = Integer.parseInt(str, 16);
            shortBuffer.append(chars[x % 0x3E]);
        }
        return shortBuffer.toString();
    }
}